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Old software keeping space missions alive

bbc.com

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Re: Old software keeping space missions alive

#11

Post by WalterBright »

contingencies wrote: post #2

The spacecraft doesn't have a fuel gauge ... Zoom call with 100 Airbus engineers ... The original software for part of the onboard navigation system was running on a Windows 98 PC that no-one could find the password to and ended up using bolt cutters to extract the hard drives. Talk about a deep space horror story!

The Apollo capsule didn't have a fuel gauge, either, because nobody could figure out how to make a fuel gauge work in weightless conditions. Various schemes failed. The solution turned out to be to have a reserve tank with enough propellant in it to do reentry. Then when the main tank ran dry, you knew just what you could do with what was left.

Re: Old software keeping space missions alive

#12

Post by WalterBright »

contingencies wrote: post #2

The spacecraft doesn't have a fuel gauge ... Zoom call with 100 Airbus engineers ... The original software for part of the onboard navigation system was running on a Windows 98 PC that no-one could find the password to and ended up using bolt cutters to extract the hard drives. Talk about a deep space horror story!

Why would anyone need bolt cutters to extract the drives? I have a couple Win98 PCs in the basement, and you just unscrew the drives. The password on it didn't encrypt the drives, either.

As for the password, this is the old days. Could probably google how to crack the password for it. Or just try the classic 123456, querty, password, or letmein.

Re: Old software keeping space missions alive

#13

Post by barelyauser »

WalterBright wrote: post #11
contingencies wrote: post #2

The spacecraft doesn't have a fuel gauge ... Zoom call with 100 Airbus engineers ... The original software for part of the onboard navigation system was running on a Windows 98 PC that no-one could find the password to and ended up using bolt cutters to extract the hard drives. Talk about a deep space horror story!

The Apollo capsule didn't have a fuel gauge, either, because nobody could figure out how to make a fuel gauge work in weightless conditions. Various schemes failed. The solution turned out to be to have a reserve tank with enough propellant in it to do reentry. Then when the main tank ran dry, you knew just what you could do with what was left.

Since you know how much fuel you start with, can't you integrate something like the time spent firing the engine and use that as gauge?

Re: Old software keeping space missions alive

#14

Post by dr_orpheus »

contingencies wrote: post #2

The spacecraft doesn't have a fuel gauge ... Zoom call with 100 Airbus engineers ... The original software for part of the onboard navigation system was running on a Windows 98 PC that no-one could find the password to and ended up using bolt cutters to extract the hard drives. Talk about a deep space horror story!

No spacecraft has a "fuel gauge" in the traditional sense. You don't have gravity to for a float to work like any fuel gauge in a car or airplane. Fuel is driven by surface tension and pressure rather than any buoyancy/gravity forces. These leads to the development of diaphragm type tanks where the pressurized bladder pushes fuel out of the tank or propellant management device (PMD) type tanks [0/1] that use the surface tension to guide pressurant-free fuel to the thrusters.

So determining how much fuel you have left is done by a combination of integrating how much time you had thrusters firing, coupled with what pressure the tanks/lines were at while the thrusters were firing. Errors in these measurements accumulate over time which is why there is a lot of effort in to determining how much fuel is left in a spacecraft. Especially critical for things like big comm birds in GEO where fuel can be limiting in operation and the more fuel you have the longer you can keep station and get revenue from the satellite. But you need to still be conservative enough to have enough fuel to get out of the GEO belt for decommissioning your satellite.

[0] https://en.wikipedia.org/wiki/Propellant_management_device [1] https://www.northropgrumman.com/space/pmd-tanks/

Re: Old software keeping space missions alive

#15

Post by RugnirViking »

dr_orpheus wrote: post #14
contingencies wrote: post #2

The spacecraft doesn't have a fuel gauge ... Zoom call with 100 Airbus engineers ... The original software for part of the onboard navigation system was running on a Windows 98 PC that no-one could find the password to and ended up using bolt cutters to extract the hard drives. Talk about a deep space horror story!

No spacecraft has a "fuel gauge" in the traditional sense. You don't have gravity to for a float to work like any fuel gauge in a car or airplane. Fuel is driven by surface tension and pressure rather than any buoyancy/gravity forces. These leads to the development of diaphragm type tanks where the pressurized bladder pushes fuel out of the tank or propellant management device (PMD) type tanks [0/1] that use the surf…

I'm sure we'll get there eventually. But there is a fun idea in there somewhere about a future where the only need for manned spaceflight is so we can get pinged by the computer once every few days and go and hug/wrap a tape measure around the fuel bladder

Re: Old software keeping space missions alive

#16

Post by cryptoz »

snickerbockers wrote: post #4

jesus christ, i dont think ive ever seen an article that beats around the bush for as long as this one does before finally getting to the point. anyways, for those who don't have the patience, the title is misleading. it's just some old software from the 90s. It's only ancient if you're one of those people who completely rewrites their entire code base from the ground up every two years because to pad out your resume…

Software does degrade with age, though. Simply the fact that vulnerabilities are found over time means that our understanding of a piece of software and how it works changes. But it's not just vulnerabilities being found, it's protocols used that may be unsupported etc. That change is a kind of a rot like people call 'bit rot' but it's a specific software rot that does happen. Systems are complicated.

Re: Old software keeping space missions alive

#17

Post by mikestew »

WalterBright wrote: post #12
contingencies wrote: post #2

The spacecraft doesn't have a fuel gauge ... Zoom call with 100 Airbus engineers ... The original software for part of the onboard navigation system was running on a Windows 98 PC that no-one could find the password to and ended up using bolt cutters to extract the hard drives. Talk about a deep space horror story!

Why would anyone need bolt cutters to extract the drives? I have a couple Win98 PCs in the basement, and you just unscrew the drives. The password on it didn't encrypt the drives, either. As for the password, this is the old days. Could probably google how to crack the password for it. Or just try the classic 123456, querty, password, or letmein.

Why would anyone need bolt cutters to extract the drives?

I've had PC cases that had eyelets for a lock. You'd have to get through that before "unscrew(ing) the drives".

Re: Old software keeping space missions alive

#18

Post by CoastalCoder »

peraspera wrote: post #9
snickerbockers wrote: post #4

jesus christ, i dont think ive ever seen an article that beats around the bush for as long as this one does before finally getting to the point. anyways, for those who don't have the patience, the title is misleading. it's just some old software from the 90s. It's only ancient if you're one of those people who completely rewrites their entire code base from the ground up every two years because to pad out your resume…

Not to mention that they confuse RAM with storage. The iPhone 14 certainly doesn't have a minimum of 128 GB of RAM.

Depending on context and the audience, it could be fair to use "RAM" to refer to SSD storage.

SSDs are random access, just not volatile like DRAM.

Re: Old software keeping space missions alive

#19

Post by CoastalCoder »

hilbert42 wrote: post #3

How about traveling-wave vacuum tubes from the pre-transistor era. Doesn't Voyager use them to generate its RF transmission power?

Slightly tangential, but if money were no object, do vacuum tubes or solid-state amps have a longer service life in this kind of application?

Re: Old software keeping space missions alive

#20

Post by ericbarrett »

justinator wrote: post #5
snickerbockers wrote: post #4

jesus christ, i dont think ive ever seen an article that beats around the bush for as long as this one does before finally getting to the point. anyways, for those who don't have the patience, the title is misleading. it's just some old software from the 90s. It's only ancient if you're one of those people who completely rewrites their entire code base from the ground up every two years because to pad out your resume…

There's a little more to it. If your original team retires because of old age, that's a lot of wisdom lost. Not everyone wants to learn COBOL to keep planes in the air and the IRS running, imagine needing to figure out the low level code on something millions of miles away with half the hardware broken, the battery cracked and leaking – and if the software update doesn't work, the entire mission is over? It's altoget…

COBOL is really quite straightforward and readable. I don't think a developer who's already familiar with a modern language or two would have a hard time picking it up. The system it's operating is domain-specific knowledge anyway, and would be something a newcomer would have to learn (or be familiar with) regardless of language.
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